Joy stick control mechanism with movable printed circuit switch assembly controlling motor input power polarity

ABSTRACT

A control mechanism is disclosed embodying a pivot shaft which controls the supply of power to an electric motor, such as utilized for rotating revolving searchlights. A universal pivotal mounting arrangement is provided for the pivot shaft which does not require a conventional ball and socket joint. When the shaft is pivoted in one direction, it shifts a free-floating printed circuit board to energize the motor. When the shaft is pivoted in the opposite direction, the printed circuit board effects reversal of the polarity of the input power to the motor. In the preferred embodiment, the pivot shaft is pivotal about perpendicularly extending axes to control two electric motors simultaneously whereby a searchlight may be rotated both vertically and horizontally at the same time.

United States Patent [191 Dufresne JOY STICK CONTROL MECHANISM WITH.MOVABLE PRINTED CIRCUIT SWITCH ASSEMBLY CONTROLLING MOTOR INPUT POWERPOLARITY Inventor: Webster J. Dufresne, Costa Mesa,

Calif.

International Telephone and Telegraph Corporation, New York, NY.

Assignee:

Filed: June 4, 1973 Appl. No.: 366,705

References Cited UNlTED STATES PATENTS 6/1960 Lybrook et al. 200/6 A4/1962 Barcus et al. 200/6 A X 5/1963 Wright 200/166 PC X 3/1967 Jonsson200/6 A X Sept. 10, 1974 3,643,294 2/ 1972 Wilson 200/6 A X 3,644,7282/1972 Hessemer et a1. 240/619 3,708,636 [/1973 Sobchak 200/6 A3,736,390 5/1973 Lockard 200/11 DA 3,770,915 11/1973 Bennett et a1.200/6 A Primary Examiner.lames R. Scott Attorney, Agent, or Firm-ThomasL. Peterson [5 7] ABSTRACT A control mechanism is disclosed embodying apivot shaft which controls the supply of power to an electric motor,such as utilized for rotating revolving searchlights. A universalpivotal mounting arrangement is provided for the pivot shaft which doesnot require a conventional ball and socket joint. When the shaft ispivoted in one direction, it shifts a free-floating printed circuitboard to energize the motor. When the shaft is pivoted in the oppositedirection, the printed circuit board effects reversal of the polarity ofthe input power to the motor. In the preferred embodiment, the pivotshaft is pivotal about perpendicularly extending axes to control twoelectric motors simultaneously whereby a Searchlight may be rotated bothvertically and horizontally at the same time.

23 Claims, 5 Drawing Figures PATENIED SEP 1 01974 SHEET 2 or 2 JOY STICKCONTROL MECHANISM WITH MOVABLE PRINTED CIRCUIT SWITCH ASSEMBLYCONTROLLING MOTOR INPUT POWER POLARITY BACKGROUND OF THE INVENTION Thisinvention relates generally to a control mechanism for an electric motorand, more particularly, to a control mechanism employing a pivotal shaftfor controlling electric power delivered to one or a pair of electricmotors.

Control mechanisms utilized for revolving lights or similar rotatingdevices generally employ a pivot shaft which is commonly referred to inthe art as a joy stick. Examples of revolving lights which require sucha control mechanism are disclosed in US. Pat. Nos. 2,762,994; 2,578,239;and 3,117,302. In such lights, a single motor is employed for rotatingthe lights about a vertical axis. More recently, revolving lights havebeen used which will rotate about both vertical and horizontal axes,thus requiring a pair of electric motors for rotating the lights in thismanner. A revolving light of this type is disclosed in U.S. Pat. No.3,644,728. The pivot shafts utilized in the control mechanisms for theseprior art lights have typically employed conventional ball and socketjoints which are relatively expensive or have not been as rugged as isrequired for some applications. Moreover, the control mechanisms forrevolving lights of the type disclosed in the aforementioned US. Pat.No. 3,644,728 have not been capable of providing simultaneous control ofpower to the two electric motors to permit rapid vertical and horizontalpositioning of the lights.

It is, therefore, the object of the present invention to overcome theattendant disadvantages of abovementioned control mechanisms byproviding a pivot shaft structure which is relatively rugged, yetinexpensive, and which permits simultaneous control of two motors toprovide rapid universal positioning of rotatable elements controlled bythe motors.

SUMMARY OF THE INVENTION According to the principal aspect of thepresent invention, there is provided a control mechanism for rotatablelights or the like including a pivot shaft which normally lies coaxialwith a vertical axis and is pivotal in opposite directions about an axisextending perpendicular to the vertical axis to first and secondpositions. A fixed insulative plate carrying a pair of contact elementssurrounds the pivot shaft. The contact elements are adapted to beconnected to an electric motor utilized for rotating the light. Eachcontact element is formed with a contact engaging area. A laterallyshiftable annular printed circuit board is positioned to surround thepivot shaft and engage the contact elements. This board is provided withspaced inner and outer circular conductive layers which face the contactelements. The two layers are adapted to be connected to the positive andnegative terminals, respectively, of an electric power supply. When thepivot shaft is coaxial with the aforementioned vertical axis, thecontact engaging areas of the contact elements are arranged to lie outof engagement with both the inner and outer conductive layers on theprinted circuit board so that no power will flow to the motor. When thepivot shaft is pivoted to the first position, the contact engaging areaof one of the contact. elements engages the outer conductive layer onthe printed circuit board and the contact engaging area of the othercontact element engages the inner conductive layer, whereby power willbe supplied to the motor to rotate it in one direction. In the secondposition of the pivot shaft, the contact engaging area of said onecontact element engages the inner conductive layer on the printedcircuit board and the contact engaging area of the other contact elementengages the outer conductive layer whereby there occurs a reversal ofpolarity of the power delivered to the motor, thus rotating the motor inthe opposite direction. Preferably, the pivot shaft is also pivotalabout a second axis perpendicular to the vertical and laterallyextending axes so that the pivot shaft is universally pivotal about acentral pivot point. A second pair of contact elements, connected to asecond electric motor, are positioned on the insulative plate so as toengage the inner and outer conductive layers on the printed circuitboard when the pivot shaft is pivoted about the aforementionedperpendicular axis. By this arrangement, the supply of power to the twomotors may be controlled simultaneously so as to rotate the light aboutboth vertical and horizontal axes via the two electric motors.

According to another aspect of the present invention, the pivot shaft ismounted axially within a housing formed with aligned bores of differentdiameter, defining therebetween a flat annular shoulder. An outwardlyextending flange is formed on the portion of the shaft lying in thelarger diameter bore. This flange is urged into engagement with theannular shoulder by means of a spring, which retains the shaft axiallypositioned in the bores. The diameter of the shaft in the two bores isless than that of the bores so as to permit the shaft to be rocked orpivoted about an axis extending laterally through the axis of the boresnear the flange on the shaft. This structure is relatively rugged and,therefore, withstands heavy loads. It also permits close and positivepositioning of the shaft to thereby provide accurate control of powersupplied to the electric motors described in the aforementioned controlmechanism.

Other aspects and advantages of the invention will become more apparentfrom the following description taken in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration ofthe control mechanism of the present invention showing the relativeposition of the pivot shaft with respect to a fixed printed circuitboard having contact elements thereon adapted to be connected to a pairof electric motors and a movable printed circuit board having conductivelayers thereon adapted to be connected to a power supply;

FIG. 2 is a bottom plan view of the fixed printed circuit boardillustrated in FIG. 1 showing how the pair of electric motors areconnected to the contact elements on the board;

FIG. 3 is a fragmentary side view of the board illustrated in FIG. 2taken along line 3-3, showing the configuration of a contact element onthe board;

FIG. 4 is a top plan view of the movable printed circuit boardillustrated in FIG. 1 shown connected to a power supply; and

FIG. 5 is a partial longitudinal sectional view through a preferred formof the pivot shaft structure of the present invention embodied in acontrol mechanism as illustrated in FIGS. 1-4 with the shaft shown infull lines in its normal position; the pivot shaft and the movableprinted circuit board are also shown in phantom in the position theseelements would assume when the shaft is pivoted from its normal positionabout one of its laterally extending pivot axes.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings indetail, there is schematically illustrated in FIG. 1 the controlmechanism of the present invention, generally designated 10. The controlmechanism includes an elongated pivot shaft or joy stick 12 whichnormally lies coaxial with a vertically extending axis ZZ. The shaft 12is pivotal in opposite directions about an axis X-X which extendsperpendicular to and passes through the vertical axis ZZ. The shaft isalso pivotal in opposite directions about an axis Y-Y which passesthrough the intersection of the XX and ZZ axes and is perpendicular toboth of these axes. Thus, the shaft 12 is universally pivotal aboutpoint 14 which is the point of intersection of the three axes.

A fixed printed circuit board 16 formed with a central circular opening17 surrounds the shaft 12 below the pivot point 14. The board 16 ispositioned so that the center of the opening 17 therein is coaxial withthe vertical axis ZZ. The printed circuit board 16 comprises aninsulative substrate 18 on which there are mounted four contact elements20, 22, 24, 26. As best seen in FIG. 3, each contact element is formedwith a downwardly extending resilient arm 28 which is turned up at itsend 30 providing therebetween a downwardly facing convex contactengaging area 32. The contact elements 24 and 26 are positioned on thesubstrate 18 so that their respective contact engaging areas 32 lie onan imaginary straight line AA passing through the center of the hole 17and thus the axis ZZ. The contact elements and 22 are positioned on thesubstrate 18 so that their respective contact engaging areas 32 lie onan imaginary straight line BB which is perpendicular to the line A-A andpasses through the intersection of the line A-A and the axis Z-Z. Theline AA is parallel to the axis XX while the line B-B is parallel to theaxis Y-Y. The contact engaging areas 32 of the four contact elements arepositioned equidistant from the center of the hole 17 and thus lie in acircular path indicated at 34 in FIG. 2 which is coaxial with thevertical axis ZZ. Conductive layers 36, 38, 40 and 42 on the lowersurface of the substrate 18 extend from the bases of the contactelements 20, 24, 22 and 26, respectively, to an outer peripheral region44 on the substrate. The conductive layers are positioned closely to oneanother to facilitate the wiring of conductors thereto. The conductivelayers 36 and 40 are connected to one electric motor Ml while theconductive layers 38 and 42 are connected to a second electric motor M2.The printed circuit board 16 constitutes a power takeoff board fordelivering electric power to motors M1 and M2.

A free-floating laterally movable printed circuit board 50 is positionedbelow the power takeoff board 16. The board 50 is free floating since itis not secured to any fixed structure and is free to move in anydirection in a horizontal plane. The board 50 is in the form of anannular ring having a central circular opening 52 therein which has adiameter greater than that of the shaft 12 but less than that of theopening 17 in the power takeoff board. The printed circuit board 50 isnormally positioned coaxial with respect to the axis Z-Z. The boardcomprises an insulative plate 51. Continuous inner and outer circularlayers 54 and 56, respectively, are formed on the upper surface of theplate so as to face the contact elements mounted on the power takeoffboard 16. The layer 54 and 56 are spaced radially from one another toprovide a nonconductive annular face 58 therebetween. A plated throughhole 59 is formed through the board 50 at the inner layer 54. A radiallyextending conductive strip 62 on the lower surface of the board 50extends from the outer periphery 64 of the board to the plated throughhole 59.

The positive terminal of a power supply 66 is connected to the outerconductive layer 56 and the negative terminal of the power supply isconnected, as by soldering, to the strip 62 leading to the innerconductive layer 54 through the plated through hole 59, as best seen inFIG. 4. The printed circuit board 50, therefore, constitutes the powercontact board of the contro mechanism 10.

The width of the contact engaging areas 32 on the contact elements 20,22, 24 and 26 is slightly less than the width of the inner and outerconductive layers 54 and 56 and of the nonconductive annular surface 58therebetween. With the power contact board 50 normally positionedcoaxial with respect to the axis ZZ, the nonconductive annular surface58 on the board will lie in concentric alignment with the circular path34 on the power takeoff board so that the contact engaging areas of thecontact elements will engage only such nonconductive surface and thuswill be out of engagement with both the inner and outer conductivelayers 54 and 56. Hence, with the printed circuit board 50 so disposed,no power from the supply 66 will be conveyed to either of the sets ofcontact elements 20-22 or 2426. If the pivot shaft 12 is pivoted aroundthe YY axis so as to shift the lower end of the shaft in the rightwarddirection as viewed in FIG. 1, the inner conductive layer 54 on thepower contact board 50 will come into engagement with the contactengaging area 32 of the contact element 24 and the outer conductivelayer 56 will come into contact with the contact engaging area of thecontact element 26 so that current will flow from the power supply 66through the outer conductive layer 56 to the contact element 26 and fromthe contact element 26 through the conductive layer 42 on the powertakeoff board to one terminal of the motor M2. The current will thenflow from the other terminal of the motor through the conductive layer38, contact element 24 and inner conductive layer 54 on the powercontact board back to the supply 66, thereby energizing the motor M2 torotate in one direction. If the lower end of the shaft 12 is pivotedabout the axis Y-Y in the leftward direction as viewed in FIG. 1, thecontact element 24 will engage the outer conductive layer 56 on thepower contact board and the contact element 26 will engage the innerconductive layer 54, thereby reversing the polarity of the powersupplied to the motor M2 and reversing the direction of rotation of themotor. It will be appreciated that when the pivot shaft 12 is pivotedabout the axis X--X, the motor M1 will be energized in the same manneras the motor M2.

If the shaft 12 is pivoted about both the XX and YY axes within any oneof the four arcuate regions indicated by the angle R appearing in FIG.1, two of the contact elements will engage the inner conductive layer,and the other two contacts will engage the outer conductive layer on thepower contact board so that power will be supplied simultaneously toboth the motors M1 and M2. Each arcuate area indicated by the angle R inFIG. 1 covers approximately 30, and the radial limits of the area aredisposed about 30 from the XX and YY axes..Thus, the pivot shaft, beinguniversally pivotal about both the axes XX and Y-Y, allows not onlyindependent control of the motors M1 and M2 but also simultaneouscontrol of the motors so that a mechanism which is rotatable about bothvertical and horizontal axes, for example, can be controlled formovement about both such axes simultaneously. Also, the controlmechanism of the present invention permits reversal of the polarity ofthe power supplied to both the motors.

Reference is now made to FIG. 5 of the drawings which shows thepreferred form of the pivot shaft mounting arrangement of the presentinvention embodied in a control mechanism as shown schematically inFIG. 1. As seen in FIG. 5, the shaft 12 includes an upper, relativelysmall diameter section 70 and a lower, relatively large diameter section72. The pivot shaft is mounted coaxially within a vertically extendingbore 74 formed in a support body 76. The axis of the bore corresponds tothe axis ZZ in FIG. 1. The support body is mounted on a face plate 78 bya series of screws 80. The bore 74 in the support body includes anupper, relatively small diameter portion 82 and a lower, relativelylarge diameter portion 84 joined to one another by a flat annularshoulder 86. The shoulder 86 lies in a plane which is perpendicular tothe axis of the bore 74. The diameter of the upper section 70 of theshaft is less than the diameter of the upper portion 82 of the bore andthe diameter of the lower section 72 of the shaft is less than that ofthe lower portion 84 of the bore. An annular flange 88 is formed on thelower section 72 of the shaft adjacent to the upper section 70. Theouter periphery 90 of the flange 88 is spaced slightly from the wall ofthe bore portion 84 so as to allow the pivot shaft 12 to rock or pivotabout a point generally located at the position indicated by referencenumeral 91 which lies on the axis of the bore 74. Preferably the upper,outer edge 92 of the flange is rounded as is the junction of the wall ofthe lower bore portion 84 and the flat annular shoulder 82 to facilitaterocking action of the shaft 12 within the bore 74.

The power takeoff board 16 is mounted on the lower surface of thesupport body 76 by a plurality of screws 96. The diameter of the opening17 in the board 16 is less than that of the lower bore portion 84 sothat the inner periphery of the board will extend inwardly from thesurface of the bore to define an annular flange 98. A generallyconically shaped coiled compression spring 100 is positioned in thelower bore portion 84 with the lower, larger diameter end of the springengaging the flange 9,8 and the upper, smaller diameter end of thespring engaging the flange 88 on the shaft 12. The upper surface 101 ofthe flange 88 is flat and lies in a plane which is perpendicular to theaxis of the shaft. Thus, it will be appreciated that the compressionspring 100 will urge the flat upper surface on the flange 88 intoengagement with flat annular shoulder 86 in the support body to normallyretain the shaft positioned coaxially within the bore 74.

As will be appreciated from the foregoing, the shaft 12 is capable ofbeing pivoted within the support body 76 by exerting a lateral forceagainst the upper section of the shaft. The shaft will rock about thepivot point 91 in any direction. The point 91 corresponds to the pivotpoint 14 in FIG. 1. As will be appreciated, the point 91 shifts slightlyin the vertical direction in the region of the flange 84 on the shaftdue to the arrangement which allows the shaft to make a rocking motionwithin the support body 76.

The upper portion 102 of the support body 76 extends through an opening104 formed in the plate 78. A rubber boot seal 106 is engaged with theupper portion 102 of the support body. A handle 108 is mounted on theupper section 70 of the shaft. The boot seal is sealed to the lowersurface 110 of the handle so that the interior of the support body isprotected from the external environment above the plate 78.

The power contact board 50 is positioned below the power takeoff board16 and surrounds the lower section 72 of the shaft 12. The diameter ofthe opening 52 in the power contact board is less than the diameter ofthe opening 17 in the power takeoff board but slightly greater than thediameter of the lower section 72 of the shaft to provide a sliding fittherebetween. Thus, when the shaft 12 is pivoted, it will engage theboard 50 to shift it laterally without engaging the board 16. Preferablythe insulative plate 51 of the board 50 is chamfered adjacent theopening 52 to form a knife edge which provides a line contact betweenthe board and the lower section 72 of the pivot shaft. The line contactpermits relatively sensitive and accurate control of the position of thepower contact board 50 upon pivoting of the shaft 12.

A retaining ring 12 is positioned in a groove 114 adjacent the lower end116 of the shaft 12. A generally conical shaped coil compression spring118 surrounds the lower section 72 of the shaft with the lower, smallerdiameter end of the spring engaging the retaining ring 112 and theupper, larger diameter end of the spring engaging the lower surface ofthe power contact board 50, thereby urging the board upwardly intoengagement with the contact engaging areas 32 on the contact elements20, 22, 24 and 26 mounted on the bottom of the board 16.

As stated previously in connection with FIG. 1, the board 50 is normallypositioned so that the contact elements on the board 16 will lie betweenthe inner and outer conductive layers 54 and 56, respectively, on theboard 50. When the pivot shaft 12 is pivoted about the point from theposition shown in full lines in FIG. 5 to the position shown in phantom,the board 50 will be shifted in the leftward direction as viewed in FIG.5 bringing the inner conductive layer 54 on the board 50 into engagementwith one contact element 22 and the outer conductive layer 56 intoengagement with the diametrically oppositely positioned contact element20 whereby power will be supplied to the motor M1. It will beappreciated that by pivoting the shaft about the point 91 in a verticalplane passing through the axis of the bore 74, the inner and outerconductive layers 54 and 56 on the board 50 will come into engagementwith the contact element 24 and 26, respectively, thereby energizing themotor M2.

By pivoting the shaft 12 in opposite directions about the point 90, theoperator can reverse the polarity of the power supplied to the motors M1and M2. Also, by pivoting the shaft in the four arcuate areas indicatedby angle R in FIG. 1, both the motors M1 and M2 will be energizedsimultaneously. In addition, because of the pivotal construction of theshaft 12 in the support body 76 described herein, a universal pivotingaction is permitted without the requirement of a ball and socket joint.The pivotal arrangement provided by the present invention is relativelyinexpensive yet is quite rugged and therefore can withstand relativelyheavy loads.

While the control mechanism of the present invention has beenspecifically described herein for use with revolving search lights, theinvention is not limited to such use but may be utilized for controllinginput power to one or two motors used for any purpose, such as rotatingspeakers, antennas or the like.

What is claimed is:

1. A control mechanism comprising:

a support body having a bore therethrough extending from a front face toa rear face thereof, said bore comprising a smaller diameter portionopening at said front face and a larger diameter portion opening at saidrear face, said bore portions being joined by an annular shoulder;

a pivot shaft extending axially through said bore beyond said front andrear faces, said pivot shaft having a first section positioned in saidsmaller diameter bore portion and a second section positioned in saidlarger diameter bore portion, said first and second sections havingdiameters less than that of said smaller and larger diameter boreportions, respectively;

an outwardly extending flange on said second section of said shaft nearsaid first section and having a diameter slightly less than that of saidlarger diameter bore portion providing a clearance space therebetweensufficient to permit said shaft to be pivoted about an axis extendinglaterally through the center of said second section adjacent saidflange;

spring means engaging said pivot shaft to bias said flange toward saidannular shoulder to resiliently retain said pivot shaft axiallypositioned in said bore;

an insulative plate surrounding said pivot shaft adjacent the rear faceof said body and being fixed relative to said body;

a pair of contact elements mounted on the side of said plate oppositesaid body, each contact element being formed with a contact engagingarea;

an annular printed circuit board closely surrounding said second sectionof said pivot shaft, said board having spaced inner and outer circularconductive layers thereon facing said contact elements;

means mounting said board for lateral movement relative to said plateand positioning said board to engage said contact elements;

said contact engaging areas of said contact elements being arranged tolie out of engagement with both said inner and outer conductive layerswhen said pivot shaft is axially positioned in said bore;

said pivot shaft being pivotal in opposite directions from the axis ofsaid bore to first and second positions;

in said first position of said pivot shaft, the contact engaging area ofone of said contact elements engaging said outer conductive layer andthe contact engaging area of the other contact element engaging theinner conductive layer; and

in said second position of said pivot shaft, the contact engaging areaof said one contact element engaging said inner conductive layer and thecontact engaging area of said other contact element engaging said outerconductive area.

2. A control mechanism as set forth in claim 1 10 wherein:

a flange extends radially inwardly into said larger diameter boreportion from said support body adjacent to said rear face; and

said spring means comprises a coiled compression spring surrounding saidsecond section of said pivot shaft with one end of said spring engagingsaid inwardly extending flange and the other end of said spring engagingsaid outwardly extending flange on said pivot shaft.

3. A control mechanism as set forth in claim 1 cent the end of saidsecond section; and

said mounting means comprises a coiled compression spring surroundingsaid second section with one end of said spring engaging said secondflange and the other end of said spring engaging said printed circuitboard to bias said board into engagement with said contact elements.

4. A control mechanism as set forth in claim 1 wherein:

each said inner and outer conductive layer is a continuous ring,

said outer conductive layer lies adjacent to the outer periphery of saidboard; and including a plated through hole in said board extending fromsaid inner conductive layer to the surface of said board opposite thesurface carrying said layers; and

a radially extending conductive strip on said opposite surface extendingfrom said periphery to said plated through hole.

5. A control mechanism as set forth in claim 1 wherein:

said fixed insulative plate is a printed circuit board mounted on saidrear face of said body having an opening therethrough receiving saidpivot shaft, said board having conductive layers thereon extending fromsaid contact elements to an outer pe ripheral region of said board.

6. A control mechanism as set forth in claim 1 wherein:

said contact engaging areas of said contact elements are spacedequidistant from the axis of said bore.

said insulative plate carrying a second pair of said contact elements,the contact engaging areas of sald second pair lying on an imaginarystraight line generally normal to an imaginary straight line passingthrough the contact engaging areas of said firstmentioned pair ofcontact elements; and

one of said imaginary lines being parallel to said firstmentioned axisand the other imaginary line being parallel to said second axis.

8. A control mechanism as set forth in claim 7 wherein:

said contact engaging areas of said first and second pair of contactelements lie in a circular path concentric with the axis of said bore;and

said circular path lies between said printed circuit board inner andouter conductive layers when said pivot shaft is axially aligned in saidbore.

9. A control mechanism comprising:

pivot shaft means normally lying coaxial with a vertical axis and beingpivotal in opposite directions about an axis extending perpendicular tosaid vertical axis to first and second positions,

a fixed insulative plate surrounding said pivot shaft means;

a pair of contact elements mounted on said plate, each contact elementbeing formed with a contact engaging area;

an annular printed circuit board closely surrounding said pivot shaftmeans, said board having spaced inner and outer circular conductivelayers thereon facing said contact elements;

means mounting said board for lateral movement relative to said plateand positioning said board to engage said contacts;

said contact engaging areas of said contact elements being arranged tolie out of engagement with both said inner and outer conductive layerswhen said pivot shaft means is coaxial with said vertical axis;

in said first position of said pivot shaft means, the

contact engaging area of one of said contact elements engaging saidouter conductive layer and the contact engaging area of the othercontact element engaging the inner conductive layer; and

in said second position of said pivot shaft means, the

contact engaging area of said one contact element engaging said innerconductive layer and the contact engaging area of said other contactelement engaging said outer conductive layer.

10. A control mechanism as set forth in claim 9 wherein said printedcircuit board is free-floating and said mounting means including:

means biasing saId board into engagement with said contact elements.

11. A control mechanism as set forth in claim 9 wherein each said innerand outer conductive layer is a continuous ring,

said outer conductive layer lies adjacent to the outer periphery of saidboard; and including a plated through hole in said board extending fromsaid inner conductive layer to the surface of said board opposite thesurface carrying said layers; and

a radially extending conductive strip on said opposite surface extendingfrom said periphery to said plated through hole.

12. A control mechanism as set forth in claim 9 wherein:

said fixed insulative plate is a printed circuit board having an openingtherethrough receiving said pivot shaft means and having conductivelayers thereon extending from said contact elements to an outerperipheral region of said board.

13. A control mechanism as set forth in claim 9 wherein:

said contact engaging areas of said contact elements are spacedequidistant from said vertical axis.

14. A control mechanism as set forth in claim 9 wherein:

said pivot shaft means is also pivotal about a second axis passingthrough said vertical axis and generally normal to said perpendicularaxis;

.said insulative plate carrying a second pair of said contact elements,the contact engaging areas of said second pair lying on an imaginaryline generally normal to an imaginary straight line passing through thecontact engaging areas of said firstmentioned pair of contact elements;and

one of said imaginary lines being parallel to said perpendicular axisand the other imaginary line being parallel to said second axis.

15. A control mechanism as set forth in claim 14 wherein:

said contact engaging areas of said first and second pair of contactelements lie in a circular path concentric with said vertical axis; and

said circular path lies between said printed circuit board inner andouter conductive layers when said pivot shaft is coaxial with saidvertical axis.

16. A control mechanism as set forth in claim 14 including:

a power supply having positive and negative terminals;

means electrically connecting one of said terminals to said innerconductive layer and the other terminal to said outer conductive layer;

first and second electric motors;

means electrically connecting said first motor to said firstmentionedpair of contact elements and said second motor to said second pair ofcontact elements.

17. A control mechanism as set forth in claim 9 wherein said printedcircuit board is free-floating and a flange is formed on said pivotshaft means on the side of said board opposite said conductive layers,and said mounting means including:

a coiled compression spring surrounding said pivot shaft with one end ofsaid spring engaging said flange and the other end of said springengaging said board to bias said board toward said contact elements.

18. A control mechanism as set forth in claim 9 including:

a power supply having positive and negative terminals;

means electrically connecting one of said terminals to said innerconductive layer and the other terminal to said outer conductive layer;

an electric motor; and

means electrically connecting said motor to said pair of contactelements.

19. A control mechanism comprising:

first and second generally parallel insulative plates;

a pair of spaced contacts on the surface of said first plate facing saidsecond plate, each said contact being formed with a contact engagingarea;

spaced inner and outer circular conductive layers on the surface of saidsecond plate facing said first plate;

one of said plates being movable and the other plate being fixed; meanspositioning said one plate in a central position relative to said otherplate, in said central position of said one plate, said contacts on saidfirst plate engaging said surface of said second plate between saidspaced inner and outer conductive layers;

means for shifting said one plate from said central position in oppositedirections in a plane including said one plate to first and secondpositions;

in said first position of said one plate, the contact engaging area ofone of said contacts engaging said outer conductive layer and thecontact engaging area of the other contact engaging said innerconductive layer; and

in said second position of said one plate, the contact engaging area ofsaid one contact engaging said inner conductive layer and the contactengaging area of said other contact engaging said outer conductivelayer.

20. A control mechanism as set forth in claim 19 wherein: said shiftingmeans comprises a joy stick coupled to said one plate.

21. A control mechanism as set forth in claim 19 wherein:

said first plate carries a second pair of said contacts on said surfacethereof, the contact engaging areas of said first-mentioned and secondpairs of contacts lying on two imaginary straight lines, respectively,intersecting one another at a right angle, said contacting engagingareas being equidistant from the point of intersection of said imaginarylines; and said shifting means permitting said one plate to be shiftedfrom said central position outwardly in any direction from said point insaid plane. 22. A control mechanism as set forth in claim 21 wherein:

said shifting means comprises a universally pivotal joy stick engagingsaid one plate. 23. A control mechanism as set forth in claim 21including:

a power supply having positive and negative terminals; meanselectrically connecting one of said terminals to said inner conductivelayer and the other termina] to said outer conductive layer; first andsecond electric motors; means electrically connecting said first motorto said first-mentioned pair of contacts and said second motor to saidsecond pair of contacts.

1. A control mechanism comprising: a support body having a boretherethrough extending from a front face to a rear face thereof, saidbore comprising a smaller diameter portion opening at said front faceand a larger diameter portion opening at said rear face, said boreportions being joined by an annular shoulder; a pivot shaft extendingaxially through said bore beyond said front and rear faces, said pivotshaft having a first section positioned in said smaller diameter boreportion and a second section positioned in said larger diameter boreportion, said first and second sections having diameters less than thatof said smaller and larger diameter bore poRtions, respectively; anoutwardly extending flange on said second section of said shaft nearsaid first section and having a diameter slightly less than that of saidlarger diameter bore portion providing a clearance space therebetweensufficient to permit said shaft to be pivoted about an axis extendinglaterally through the center of said second section adjacent saidflange; spring means engaging said pivot shaft to bias said flangetoward said annular shoulder to resiliently retain said pivot shaftaxially positioned in said bore; an insulative plate surrounding saidpivot shaft adjacent the rear face of said body and being fixed relativeto said body; a pair of contact elements mounted on the side of saidplate opposite said body, each contact element being formed with acontact engaging area; an annular printed circuit board closelysurrounding said second section of said pivot shaft, said board havingspaced inner and outer circular conductive layers thereon facing saidcontact elements; means mounting said board for lateral movementrelative to said plate and positioning said board to engage said contactelements; said contact engaging areas of said contact elements beingarranged to lie out of engagement with both said inner and outerconductive layers when said pivot shaft is axially positioned in saidbore; said pivot shaft being pivotal in opposite directions from theaxis of said bore to first and second positions; in said first positionof said pivot shaft, the contact engaging area of one of said contactelements engaging said outer conductive layer and the contact engagingarea of the other contact element engaging the inner conductive layer;and in said second position of said pivot shaft, the contact engagingarea of said one contact element engaging said inner conductive layerand the contact engaging area of said other contact element engagingsaid outer conductive area.
 2. A control mechanism as set forth in claim1 wherein: a flange extends radially inwardly into said larger diameterbore portion from said support body adjacent to said rear face; and saidspring means comprises a coiled compression spring surrounding saidsecond section of said pivot shaft with one end of said spring engagingsaid inwardly extending flange and the other end of said spring engagingsaid outwardly extending flange on said pivot shaft.
 3. A controlmechanism as set forth in claim 1 wherein: said printed circuit board isfree-floating; said second section of said pivot shaft is formed with asecond outwardly extending annular flange adjacent the end of saidsecond section; and said mounting means comprises a coiled compressionspring surrounding said second section with one end of said springengaging said second flange and the other end of said spring engagingsaid printed circuit board to bias said board into engagement with saidcontact elements.
 4. A control mechanism as set forth in claim 1wherein: each said inner and outer conductive layer is a continuousring, said outer conductive layer lies adjacent to the outer peripheryof said board; and including a plated through hole in said boardextending from said inner conductive layer to the surface of said boardopposite the surface carrying said layers; and a radially extendingconductive strip on said opposite surface extending from said peripheryto said plated through hole.
 5. A control mechanism as set forth inclaim 1 wherein: said fixed insulative plate is a printed circuit boardmounted on said rear face of said body having an opening therethroughreceiving said pivot shaft, said board having conductive layers thereonextending from said contact elements to an outer peripheral region ofsaid board.
 6. A control mechanism as set forth in claim 1 wherein: saidcontact engaging areas of said contact elements are spaced equidistantfrom the axis of said bore.
 7. A control mechanism as set forth in claim1 wheRein: said pivot shaft is also pivotal about a second axis passingthrough said center of said second section and generally normal to saidlaterally extending axis; said insulative plate carrying a second pairof said contact elements, the contact engaging areas of saId second pairlying on an imaginary straight line generally normal to an imaginarystraight line passing through the contact engaging areas of saidfirst-mentioned pair of contact elements; and one of said imaginarylines being parallel to said first-mentioned axis and the otherimaginary line being parallel to said second axis.
 8. A controlmechanism as set forth in claim 7 wherein: said contact engaging areasof said first and second pair of contact elements lie in a circular pathconcentric with the axis of said bore; and said circular path liesbetween said printed circuit board inner and outer conductive layerswhen said pivot shaft is axially aligned in said bore.
 9. A controlmechanism comprising: pivot shaft means normally lying coaxial with avertical axis and being pivotal in opposite directions about an axisextending perpendicular to said vertical axis to first and secondpositions, a fixed insulative plate surrounding said pivot shaft means;a pair of contact elements mounted on said plate, each contact elementbeing formed with a contact engaging area; an annular printed circuitboard closely surrounding said pivot shaft means, said board havingspaced inner and outer circular conductive layers thereon facing saidcontact elements; means mounting said board for lateral movementrelative to said plate and positioning said board to engage saidcontacts; said contact engaging areas of said contact elements beingarranged to lie out of engagement with both said inner and outerconductive layers when said pivot shaft means is coaxial with saidvertical axis; in said first position of said pivot shaft means, thecontact engaging area of one of said contact elements engaging saidouter conductive layer and the contact engaging area of the othercontact element engaging the inner conductive layer; and in said secondposition of said pivot shaft means, the contact engaging area of saidone contact element engaging said inner conductive layer and the contactengaging area of said other contact element engaging said outerconductive layer.
 10. A control mechanism as set forth in claim 9wherein said printed circuit board is free-floating and said mountingmeans including: means biasing saId board into engagement with saidcontact elements.
 11. A control mechanism as set forth in claim 9wherein each said inner and outer conductive layer is a continuous ring,said outer conductive layer lies adjacent to the outer periphery of saidboard; and including a plated through hole in said board extending fromsaid inner conductive layer to the surface of said board opposite thesurface carrying said layers; and a radially extending conductive stripon said opposite surface extending from said periphery to said platedthrough hole.
 12. A control mechanism as set forth in claim 9 wherein:said fixed insulative plate is a printed circuit board having an openingtherethrough receiving said pivot shaft means and having conductivelayers thereon extending from said contact elements to an outerperipheral region of said board.
 13. A control mechanism as set forth inclaim 9 wherein: said contact engaging areas of said contact elementsare spaced equidistant from said vertical axis.
 14. A control mechanismas set forth in claim 9 wherein: said pivot shaft means is also pivotalabout a second axis passing through said vertical axis and generallynormal to said perpendicular axis; said insulative plate carrying asecond pair of said contact elements, the contact engaging areas of saidsecond pair lying on an imaginary line generally normal to an imaginarystraight line passing through the contact engaging Areas of saidfirst-mentioned pair of contact elements; and one of said imaginarylines being parallel to said perpendicular axis and the other imaginaryline being parallel to said second axis.
 15. A control mechanism as setforth in claim 14 wherein: said contact engaging areas of said first andsecond pair of contact elements lie in a circular path concentric withsaid vertical axis; and said circular path lies between said printedcircuit board inner and outer conductive layers when said pivot shaft iscoaxial with said vertical axis.
 16. A control mechanism as set forth inclaim 14 including: a power supply having positive and negativeterminals; means electrically connecting one of said terminals to saidinner conductive layer and the other terminal to said outer conductivelayer; first and second electric motors; means electrically connectingsaid first motor to said firstmentioned pair of contact elements andsaid second motor to said second pair of contact elements.
 17. A controlmechanism as set forth in claim 9 wherein said printed circuit board isfree-floating and a flange is formed on said pivot shaft means on theside of said board opposite said conductive layers, and said mountingmeans including: a coiled compression spring surrounding said pivotshaft with one end of said spring engaging said flange and the other endof said spring engaging said board to bias said board toward saidcontact elements.
 18. A control mechanism as set forth in claim 9including: a power supply having positive and negative terminals; meanselectrically connecting one of said terminals to said inner conductivelayer and the other terminal to said outer conductive layer; an electricmotor; and means electrically connecting said motor to said pair ofcontact elements.
 19. A control mechanism comprising: first and secondgenerally parallel insulative plates; a pair of spaced contacts on thesurface of said first plate facing said second plate, each said contactbeing formed with a contact engaging area; spaced inner and outercircular conductive layers on the surface of said second plate facingsaid first plate; one of said plates being movable and the other platebeing fixed; means positioning said one plate in a central positionrelative to said other plate, in said central position of said oneplate, said contacts on said first plate engaging said surface of saidsecond plate between said spaced inner and outer conductive layers;means for shifting said one plate from said central position in oppositedirections in a plane including said one plate to first and secondpositions; in said first position of said one plate, the contactengaging area of one of said contacts engaging said outer conductivelayer and the contact engaging area of the other contact engaging saidinner conductive layer; and in said second position of said one plate,the contact engaging area of said one contact engaging said innerconductive layer and the contact engaging area of said other contactengaging said outer conductive layer.
 20. A control mechanism as setforth in claim 19 wherein: said shifting means comprises a joy stickcoupled to said one plate.
 21. A control mechanism as set forth in claim19 wherein: said first plate carries a second pair of said contacts onsaid surface thereof, the contact engaging areas of said first-mentionedand second pairs of contacts lying on two imaginary straight lines,respectively, intersecting one another at a right angle, said contactingengaging areas being equidistant from the point of intersection of saidimaginary lines; and said shifting means permitting said one plate to beshifted from said central position outwardly in any direction from saidpoint in said plane.
 22. A control mechanism as set forth in claim 21wherein: said shifting means comprises a universally pivotal joy stickengaging said one plate.
 23. A conTrol mechanism as set forth in claim21 including: a power supply having positive and negative terminals;means electrically connecting one of said terminals to said innerconductive layer and the other terminal to said outer conductive layer;first and second electric motors; means electrically connecting saidfirst motor to said first-mentioned pair of contacts and said secondmotor to said second pair of contacts.